The S-IC and S-II stages both had early Center Engine Cutoff (S-II a bit earlier than planned on 13) and I imagine "CECO" would be pronounced the same as "SECO".

Wasn't that called Inboard Engine Cut-off, IECO instead? At least on S-IC.

The call I've heard used "inboard"...there's probably YouTube video available with that sound and the Apollo Flight Journal includes the transcripts for many of the launches. (For example, Tom Stafford called "inboard shutdown", Neil Armstrong called "inboard cutoff.")http://history.nasa.gov/afj/

This is the SM-CM umbilical. I am sure it has a fancy name and acronym. It carries power, oxygen, commands etc. between the two modules. You don't want to run these lines through the heat shield and therefore go arround it.

Analyst

Where is this prior to launch? Is it rotated somehow? Or under a fairing? I ask because it does not seem like there would be room for it under the escape tower part that covers the command module. (I forgot the name of it at the moment!)

This is the SM-CM umbilical. I am sure it has a fancy name and acronym. It carries power, oxygen, commands etc. between the two modules. You don't want to run these lines through the heat shield and therefore go arround it.

Analyst

Where is this prior to launch? Is it rotated somehow? Or under a fairing? I ask because it does not seem like there would be room for it under the escape tower part that covers the command module. (I forgot the name of it at the moment!)

Hello, Does anyone explain why during the communication between Apollo and the Houston control each communication start with a "bip" what is the usage of this "BipThanks in advance for a replyKind RegardsBernardPossible to reply on my email box [email protected]

Since the CM was designed to endure outward pressure in the vacuum of space, the plugs-out test had been run with the cabin pressure at over 16 psi, almost 2 psi above the ambient sea level pressure at Launch Complex 34 and near the upper limits of measuring devices in the spacecraft.

Since the CM was designed to endure outward pressure in the vacuum of space, the plugs-out test had been run with the cabin pressure at over 16 psi, almost 2 psi above the ambient sea level pressure at Launch Complex 34 and near the upper limits of measuring devices in the spacecraft.

I may have the units (psi) wrong, but if I recall correctly, the CM was pressurized to 5 psi. Since the atmosphere in the cabin was pure O2, this was equivalent to the partial pressure of O2 in earth's ambient atmosphere.

Since the CM was designed to endure outward pressure in the vacuum of space, the plugs-out test had been run with the cabin pressure at over 16 psi, almost 2 psi above the ambient sea level pressure at Launch Complex 34 and near the upper limits of measuring devices in the spacecraft.

I may have the units (psi) wrong, but if I recall correctly, the CM was pressurized to 5 psi.

5 psia, in space. But dks13827 is talking about Apollo 1, and he's right. The Apollo 1 plugs-out test was pressurized to 16 psia, a little less than 2 psig.

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Since the atmosphere in the cabin was pure O2, this was equivalent to the partial pressure of O2 in earth's ambient atmosphere.

Hope someone can help with this. . .During ascent and entry in the Shuttle the CDR and PLT have push-to-talk buttons on their control sticks to open their microphones and transmit voice. During Apollo, how did the crew key their microphones? ICOM may have been VOX or hot mic, but A/G was not. Were there comm control units with push-to-talk buttons in the cables connected to the suits (we see these when they strap in the Shuttle crews and do comm checks)? Or another set-up?

Hope someone can help with this. . .During ascent and entry in the Shuttle the CDR and PLT have push-to-talk buttons on their control sticks to open their microphones and transmit voice. During Apollo, how did the crew key their microphones? ICOM may have been VOX or hot mic, but A/G was not. Were there comm control units with push-to-talk buttons in the cables connected to the suits (we see these when they strap in the Shuttle crews and do comm checks)? Or another set-up?

Same as shuttle. Both the ACAs on the LM and the RCs on the CM had push-to-talk triggers.

Thanks for the prompt reply. I wasn't sure. How did the LMP transmit? Did he reach for the RHC in front of the CMP, or did he have another way to key his mic?

For the CSM, there was a rocker switch on the comm cable that could also be used to key the mike. There's a description in the Apollo Operations Handbook, section 2.8, which can be downloaded at the ALSJ:

On Apollo 12 we know the eternally famous "SCE to Aux" call. Did the call ever go up, and did the crew ever reset the SCE switch to its original setting (PRIMARY, or whatever it was)? If so, when? Can't find anything about a reset in the Apollo Flight Journal.